Inbred corn line LH252

ABSTRACT

An inbred corn line, designated LH252, is disclosed. The invention relates to the seeds of inbred corn line LH252, to the plants of inbred corn line LH252 and to methods for producing a corn plant produced by crossing the inbred line LH252 with itself or another corn line. The invention further relates to hybrid corn seeds and plants produced by crossing the inbred line LH252 with another corn line.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive corn inbred line, designated LH252. There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety or hybrid an improved combination of desirable traits from the parental germplasm. These important traits may include higher yield, resistance to diseases and insects, better stalks and roots, tolerance to drought and heat, and better agronomic quality.

Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F1 hybrid cultivar, pureline cultivar, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method. Backcross breeding is used to transfer one or a few favorable genes for a highly heritable trait into a desirable cultivar. This approach has been used extensively for breeding disease-resistant cultivars. Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination, the frequency of successful hybrids from each pollination, and the number of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding lines, and number of successful cultivars produced per unit of input (e.g., per year, per dollar expended, etc.).

Promising advanced breeding lines are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s) for three years at least. The best lines are candidates for new commercial cultivars; those still deficient in a few traits are used as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing and distribution, usually take from eight to 12 years from the time the first cross is made. Therefore, development of new cultivars is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard cultivar. If a single observation is inconclusive, replicated observations provide a better estimate of its genetic worth.

The goal of plant breeding is to develop new, unique and superior corn inbred lines and hybrids. The breeder initially selects and crosses two or more parental lines, followed by repeated selfing and selection, producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via crossing, selfing and mutations. The breeder has no direct control at the cellular level. Therefore, two breeders will never develop the same line, or even very similar lines, having the same corn traits.

Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made, during and at the end of the growing season. The inbred lines which are developed are unpredictable. This unpredictability is because the breeder's selection occurs in unique environments, with no control at the DNA level (using conventional breeding procedures), and with millions of different possible genetic combinations being generated. A breeder of ordinary skill in the art cannot predict the final resulting lines he develops, except possibly in a very gross and general fashion. The same breeder cannot produce the same line twice by using the exact same original parents and the same selection techniques. This unpredictability results in the expenditure of large research monies to develop a superior new corn inbred line.

The development of commercial corn hybrids requires the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine desirable traits from two or more inbred lines or various broad-based sources into breeding pools from which inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which have commercial potential.

Pedigree breeding is used commonly for the improvement of self-pollinating crops or inbred lines of cross-pollinating crops. Two parents which possess favorable, complementary traits are crossed to produce an F1. An F2 population is produced by selfing one or several F1's or by intercrossing two F1's (sib mating). Selection of the best individuals is usually begun in the F2 population; then, beginning in the F3, the best individuals in the best families are selected. Replicated testing of families, or hybrid combinations involving individuals of these families, often follows in the F4 generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F6 and F7), the best lines or mixtures of phenotypically similar lines are tested for potential release as new cultivars.

Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr, 1987).

Proper testing should detect any major faults and establish the level of superiority or improvement over current cultivars. In addition to showing superior performance, there must be a demand for a new cultivar that is compatible with industry standards or which creates a new market. The introduction of a new cultivar will incur additional costs to the seed producer, the grower, processor and consumer; for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new cultivar should take into consideration research and development costs as well as technical superiority of the final cultivar. For seed-propagated cultivars, it must be feasible to produce seed easily and economically.

Once the inbreds that give the best hybrid performance have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parent is maintained. A single-cross hybrid is produced when two inbred lines are crossed to produce the F1 progeny. A double-cross hybrid is produced from four inbred lines crossed in pairs (A×B and C×D) and then the two F1 hybrids are crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F1 hybrids is lost in the next generation (F2). Consequently, seed from hybrid varieties is not used for planting stock.

Corn is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop stable, high yielding corn hybrids that are agronomically sound. The reasons for this goal are obviously to maximize the amount of grain produced on the land used and to supply food for both animals and humans. To accomplish this goal, the corn breeder must select and develop corn plants that have the traits that result in superior parental lines for producing hybrids.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred corn line, designated LH252. This invention thus relates to the seeds of inbred corn line LH252, to the plants of inbred corn line LH252 and to methods for producing a corn plant produced by crossing the inbred line LH252 with itself or another corn line. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line LH252 with another corn line.

DEFINITIONS

In the description and tables which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:

Predicted RM. This trait for a hybrid, predicted relative maturity (RM), is based on the harvest moisture of the grain. The relative maturity rating is based on a known set of checks and utilizes conventional maturity systems such as the Minnesota Relative Maturity Rating System.

MN RM. This represents the Minnesota Relative Maturity Rating (MN RM) for the hybrid and is based on the harvest moisture of the grain relative to a standard set of checks of previously determined MN RM rating. Regression analysis is used to compute this rating.

Yield (Bushels/Acre). The yield in bushels/acre is the actual yield of the grain at harvest adjusted to 15.5% moisture.

Moisture. The moisture is the actual percentage moisture of the grain at harvest.

GDU Silk. The GDU silk (=heat unit silk) is the number of growing degree units (GDU) or heat units required for an inbred line or hybrid to reach silk emergence from the time of planting. Growing degree units are calculated by the Barger Method, where the heat units for a 24-hour period are: ##EQU1## The highest maximum used is 86° F. and the lowest minimum used is 50° F. For each hybrid, it takes a certain number of GDUs to reach various stages of plant development. GDUs are a way of measuring plant maturity.

Stalk Lodging. This is the percentage of plants that stalk lodge, i.e., stalk breakage, as measured by either natural lodging or pushing the stalks determining the percentage of plants that break off below the ear. This is a relative rating of a hybrid to other hybrids for standability.

Root Lodging. The root lodging is the percentage of plants that root lodge; i.e., those that lean from the vertical axis at an approximate 30° angle or greater would be counted as root lodged.

Plant Height. This is a measure of the height of the hybrid from the ground to the tip of the tassel, and is measured in centimeters.

Ear Height. The ear height is a measure from the ground to the ear node attachment, and is measured in centimeters.

Dropped Ears. This is a measure of the number of dropped ears per plot, and represents the percentage of plants that dropped an ear prior to harvest.

DETAILED DESCRIPTION OF THE INVENTION

Inbred corn line LH252 is a yellow dent corn with superior characteristics, and provides an excellent parental line in crosses for producing first generation (F₁) hybrid corn.

Inbred corn line LH252 has the following morphologic and other characteristics (based primarily on data collected at Williamsburg, Iowa):

VARIETY DESCRIPTION INFORMATION

1. TYPE: Dent

2. REGION WHERE DEVELOPED: Northcentral U.S.

3. MATURITY:

    ______________________________________                          Days  Heat Units     ______________________________________     From emergence to 50% of plants in silk:                            104     1785     From emergence to 50% of plants in pollen                             99     1675     ______________________________________      ##EQU2##

4. PLANT:

Plant Height (to tassel tip): 266 cm

Ear Height (to base of top ear): 135 cm

Length of Top Ear Internode: 19 cm

Average number of Tillers: 0

Average Number of Ears per Stalk: 1.1

Ear Tendency: Single

Anthocyanin of Brace Roots: Present

5. LEAF:

Width of Ear Node Leaf: 10 cm

Length of Ear Node Leaf: 76 cm

Number of leaves above top ear: 5

Leaf Angle from Leaf to Stalk above leaf: 50°

Leaf Color: 7.5 GY 3/4 Munsell Color Charts for Plant Tissues

Marginal Waves: Few

Longitudinal Creases: Few

6. TASSEL:

Number of Lateral Branches: 8

Branch Angle from Central Spike: 60

Tassel Length (from top leaf collar to tassel top): 48 cm

Pollen Shed: Medium

Anther Color: Yellow

Glume Color: Medium Green

Bar Glumes: Absent

7a. EAR: (Unhusked Data)

Silk Color (3 days after emergency): Red

Fresh Husk Color (25 days after 50% silking): Light Green

Dry Husk Color (65 days after 50% silking): Buff

Position of Ear: Upright

Husk Tightness: High

Husk Extension: Long (8-10 cm beyond ear tip)

7b. EAR: (Husked Ear Data)

Ear Length: 16 cm

Ear Diameter at mid-point: 40 mm

Ear Weight: 87 gm

Number of Kernel Rows: 14

Kernel Rows: Distinct

Row Alignment: Straight

Shank Length: 17.7 cm

Ear Taper: Slight

8. KERNEL: (Dried)

Kernel Length: 11 mm

Kernel Width: 10 mm

Kernel Thickness: 6 mm

Round Kernels (Shape Grade): 76%

Aleurone Color Pattern: Homozygous

Aleurone Color: White

Hard Endosperm Color: Yellow

Endosperm Type: Normal Starch

Weight per 100 kernels (unsized sample): 27.0 gm

9. COB:

Cob Diameter at Mid-Point: 30 mm

Cob Color: White

10. DISEASE RESISTANCE:

Rating

[1=(most susceptible) through 9=(most resistant)]

4 Northern Leaf Blight (Exserohilum turcicum)

8 Southern Leaf Blight (Bipolaris maydis)

8 Anthracnose (Colletotrichum graminicola)

6 Eyespot (Aureobasidium zeae)

4 Gray Leaf Spot (Cercospora zeae-maydis)

8 Helminthosporium Leaf Spot (Race 3)

This invention is also directed to methods for producing a corn plant by crossing a first parent corn plant with a second parent corn plant, wherein the first or second corn plant is the inbred corn plant from the line LH252. Further, both first and second parent corn plants may be from the inbred line LH252. Therefore, any methods using the inbred corn line LH252 are part of this invention: selfing, backcrosses, hybrid breeding, and crosses to populations. Any plants produced using inbred corn line LH252 as a parent are within the scope of this invention. Advantageously, the inbred corn line is used in crosses with other corn varieties to produce first generation (F1) corn hybrid seed and plants with superior characteristics.

As used herein, the term "plant" includes plant cells, plant protoplasts, plant cell of tissue culture from which corn plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as pollen, flowers, kernels, ears, cobs, leaves, husks, stalks, and the like.

Tissue culture of corn is described in European Patent Application, Publication No. 160,390, incorporated herein by reference. Corn tissue culture procedures are also described in Green and Rhodes, "Plant Regeneration in Tissue Culture of Maize", Maize for Biological Research (Plant Molecular Biology Association, Charlottesville, Va. 1982), at 367-372. Thus, another aspect of this invention is to provide for cells which upon growth and differentiation produce the inbred line LH252.

LH252 is a corn inbred line developed from the cross of a commercial hybrid, Pioneer Brand 3165 (P3165) with LH51. P3165 is a full season hybrid which is used primarily in the southern and southeastern areas of the United States. P3165 has demonstrated good yield potential, drought tolerance and grain quality. The other parent, LH51, first sold in 1980, was a dominant C 103 derived line throughout the 1980's and early portion of the 1990's. In recent years, LH216 has replaced LH51 in a number of hybrids with improved yield and stalk quality. Therefore, the closest related line to LH252 is LH216.

LH252 is most similar to LH216, however many differences exist between these lines. As an inbred line, cob color of LH252 is white and LH216 has a red cob. LH252 flowers 4 to 5 days later than LH216. Because of the strong influence of flowering date upon maturity, one would normally expect hybrids containing LH252 to be 1-2 percent higher in harvest moisture than comparable LH216 crosses. Unexpectedly, a number of the LH252 hybrids have demonstrated significantly lower harvest moisture. LH252 contributes excellent stress tolerance to its crosses. This was particularly evident in 1993 in the drought areas of the southeastern United States. LH252 hybrids have large plant stature and high ear placement. When compared to LH216 crosses, stalk quality of LH252 hybrids appears to be similar yet trends to the weaker side.

LH252 contributes an unusual combination of high yield potential and exceptional drydown to its hybrids. It is rare to develop hybrids which yield much higher than industry standards. In addition, the decreased harvest moistures of LH252 crosses are unexpected considering the full season nature of P3165 and the drydown rates normally associated with LH51 or LH216 in hybrid combinations.

LH252 is a late season field corn inbred. It is best adapted to the southeastern region of the corn belt. LH252 has shown good tolerance to Northern Leaf Spot Race 3, Anthracnose and Southern Leaf Blight, but is moderately susceptible to Northern Leaf Blight, Eyespot and Gray Leaf Spot.

The yield levels of LH252 hybrids are excellent. The plant profiles of crosses with LH252 are tall with high ear placement. LH252 crosses display a long ear type with excellent husk coverage and grain quality.

Some of the criteria used to select ears in various generations include: yield, stalk quality, root quality, disease tolerance, late plant greenness, late season plant intactness, ear retention, pollen shedding ability, silking ability, and corn borer toleranace. During the development of the line, crosses were made to inbred testers for the purpose of estimating the line's general and specific combining ability, and evaluations were run by the Williamsburg, Iowa Research Station. The inbred was evaluated further as a line and in numerous crosses by the Williamsburg and other research stations across the Corn Belt. The inbred has proven to have a very good combining ability in hybrid combinations.

The inbred has shown uniformity and stability for all traits, as described in the following variety description information. It has been self-pollinated and ear-rowed a sufficient number of generations, with careful attention to uniformity of plant type to ensure homozygosity and phenotypic stability. The line has been increased both by hand and sibbed in isolated fields with continued observations for uniformity. No variant traits have been observed or are expected in LH252.

TABLES

In the tables that follow, the traits and characteristics of inbred corn line LH252 are given in hybrid combination. The data collected on inbred corn line LH252 is presented for the key characteristics and traits. The tables present yield test information about LH252. LH252 was tested in several hybrid combinations at numerous locations, with two or three replications per location. Information about these hybrids, as compared to several check hybrids, is presented.

The first pedigree listed in the comparison group is the hybrid containing LH252. Information for the pedigree includes:

1. Mean yield of the hybrid across all locations.

2. A mean for the percentage moisture (% M) for the hybrid across all locations.

3. A mean of the yield divided by the percentage moisture (Y/M) for the hybrid across all locations.

4. A mean of the percentage of plants with stalk lodging (% SL) across all locations.

5. A mean of the percentage of plants with root lodging (% RL) across all locations.

6. A mean of the percentage of plants with dropped ears (% DE).

7. A mean of the plant height measured in centimeters.

8. A mean of ear height measured in centimeters.

9. The number of locations indicates the locations where these hybrids were tested together.

The series of hybrids listed under the hybrid containing LH252 are considered check hybrids. The check hybrids are compared to hybrids containing the inbred LH252.

The (+) or (-) sign in front of each number in each of the columns indicates how the mean values across plots of the hybrid containing inbred LH252 compare to the check crosses. A (+) or (-) sign in front of the number indicates that the mean of the hybrid containing inbred LH252 was greater or lesser, respectively, than the mean of the check hybrid. For example, a +4 in yield signifies that the hybrid containing inbred LH252 produced 4 bushels more corn than the check hybrid. If the value of the stalks has a (-) in front of the number 2, for example, then the hybrid containing the inbred LH252 had 2% less stalk lodging than the check hybrid.

                                      TABLE 1     __________________________________________________________________________     OVERALL COMPARISONS     LH195 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH195 × LH252               186 17.93                       10.39                           2  0  0   110 53     (at 12 Loc's)     As Compared To:     LH195 × NC258               +17 -2.25                       +2.24                           0  0  0     LH195 × LH216               +28 -.59                       +1.83                           +2 -1 0   +6  +5     LH195 × LH210               +21 -.25                       +1.32                           0  0  0   +3  +7     Pioneer 3140               +22 -.23                       +1.34                           0  -1 0   -1  +2     __________________________________________________________________________

                                      TABLE 2     __________________________________________________________________________     OVERALL COMPARISONS     LH132 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH132 × LH252               170 20.48                       8.28                           3  11 0   120 57     (at 11 Loc's)     As Compared To:     LH132 × LH60               +21 -1.74                       +1.56                           0  +5 0   +16 +13     LH195 × LH213               +9  -.88                       +.74                           0  +6 0   +8  +11     LH195 × LH51               +3  -.83                       +.48                           -1 +3 0   +9  +8     LH195 × LH216               +10 -.74                       +.76                           0  +5 0   +8  +10     LH132 × LH216               +11 +.34                       +.41                           +1 +4 0   +8  +8     __________________________________________________________________________

                                      TABLE 3     __________________________________________________________________________     OVERALL COMPARISONS     LH200 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH200 × LH252               180 19.17                       9.36                           5  3  1   116 48     (at 13 Loc's)     As Compared To:     LH195 × LH216               +6  -2.13                       +1.23                           +1 +3 0   +6  0     LH200 × LH60               +10 -2.04                       +1.27                           +1 +2 0   +13 +9     LH200 × LH213               +4  -1.02                       +.67                           +2 +2 +1  +5  +6     LH200 × LH216               +9  -1.00                       +.90                           +1 +2 0   -5  -8     LH200 × LH51               +10 -.40                       +.69                           +1 +3 0   +8  +2     __________________________________________________________________________

                                      TABLE 4     __________________________________________________________________________     OVERALL COMPARISONS     LH199 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH199 × LH252               180 18.83                       9.53                           3  1  0   119 51     (at 8 Loc's)     As Compared To:     LH197 × LH60               +12 4.79                       +2.45                           +1 +1 0   +2  +4     Pioneer 3162               +16 -3.26                       +2.12                           +2 +1 0   +9  +12     LH197 × LH216               +7  -1.88                       +1.19                           +1 0  0   -2  +2     LH132 × LH51               +17 -1.81                       +1.64                           0  +1 0   +3  +6     LH197 × LH51               +1  -1.45                       +.72                           +1 0  0   -3  +5     LH199 × LH216               +10 -.85                       +.91                           +2 +1 0   +10 +9     __________________________________________________________________________

                                      TABLE 5     __________________________________________________________________________     OVERALL COMPARISONS     LH195 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH195 × LH252               188 21.72                       8.65                           3  3  0     (at 6 Loc's)     As Compared To:     Pioneer 3167               +37 -3.57                       +2.66                           +2 0  0     LH198 × LH159               +18 -1.41                       +1.31                           +2 +2 0     LH195 × LH194               -4  -1.23                       +.14                           +8 +1 0     LH195 × LH250               +31 -.59                       +1.62                           +3 +2 0     LH195 × LH150               +18 +.23                       +.76                           +3 +3 0     LH195 × LH216               +28 +.50                       +1.13                           -1 0  0     Pioneer 3140               +3  +1.02                       -.30                           +3 +1 0     __________________________________________________________________________

                                      TABLE 6     __________________________________________________________________________     OVERALL COMPARISONS     LH200 × LH252 HYBRID VERSUS CHECK HYBRIDS               Mean        %  %  %   Plant                                         Ear     Pedigree  Yield                   % M Y/M Stalk                              Root                                 Drop                                     Height                                         Height     __________________________________________________________________________     LH200 × LH252               208 21.63                       9.62                           3  6  0   114 52     (at 16 Loc's)     As Compared To:     LH200 × LH262               -5  -.95                       +.19                           +1 +3 0   +7  +5     LH200 × LH60               +15 -.49                       +.87                           +2 +4 0   +15 +12     LH200 × LH216               +12 +.39                       +.38                           +1 +2 0   +9  +8     LH195 × LH212               +10 +1.36                       -.14                           +1 +3 0   +8  +7     LH195 × LH185               +19 +1.55                       +.23                           +1 +4 0   +16 +16     __________________________________________________________________________

DEPOSIT INFORMATION

Inbred seeds of LH252 have been placed on deposit with the American Type Culture Collection (ATCC), Rockville, Md. 20852, under Deposit Accession Number 75955 on Dec. 1, 1994. A Plant Variety Protection Certificate is being applied for with the United States Department of Agriculture.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims. 

What is claimed is:
 1. Inbred corn seed designated LH252 having ATCC accession No.
 75955. 2. A corn plant produced by growing the seed of claim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of the plant of claim
 2. 5. A tissue culture comprising regenerable cells of the inbred corn plant designated LH252, the seed of which have been deposited and have ATCC Accession No.
 75955. 6. A corn plant regenerated from the tissue culture of claim 5, wherein said corn plant has all the physiological and morphological characteristics of LH252, the seed of which have been deposited and have ATCC Accession No.
 75955. 7. A method for producing first generation (F₁) hybrid corn seed, said seed being capable of producing a hybrid corn plant having the characteristics of high yield, exceptional drydown and good root quality when compared to elite hybrids used in the southern and southeast corn growing areas of the United States, comprising crossing a first inbred parent corn plant with a second inbred parent corn plant and harvesting the resultant first generation (F₁) hybrid corn seed, wherein said first or second parent corn plant is the corn plant LH252, the seed of which have been deposited and have ATCC Accession No.
 75955. 8. The method of claim 7, wherein the first or second parent corn plant LH252, the seed of which have been deposited and have ATCC Accession No. 75955, is the female parent.
 9. The method of claim 7, wherein the first or second parent corn plant LH252, the seed of which have been deposited and have ATCC Accession No. 75955, is the male parent.
 10. A first generation (F₁) hybrid corn plant produced by growing hybrid corn seed, wherein said seed is produced by crossing a first inbred parent corn plant with a second inbred parent corn plant, wherein said first or second inbred corn plant is the corn plant of claim 2, and harvesting the resultant first generation (F₁) hybrid corn seed. 